Lubrication flow meter

ABSTRACT

The lubrication flowmeter is configured to be a part of the lubrication system to grease frack valves. The system generally utilizes a manifold to connect to the various fracked valves and at least one pressure transducer providing wellbore pressure and preferably a second pressure transducer providing grease pressure at either the manifold or the pump. A programmable logic controller is provided to activate the grease pump upon reaching preset conditions and to deactivate the grease pump upon reaching a second set of conditions such as pressure threshold, time limit, or volume limits of greased pumped.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/676,830 that was filed on May 25, 2018.

DESCRIPTION

Many industries utilize remotely actuated hydraulic valves. Such valves are relatively expensive and require significant lubrication typically using relatively expensive lubricant. Therefore, it is imperative to adequately lubricate each valve in order to maximize the valves life while at the same time not over lubricating the valves which waste the expense of lubricant. Additionally, over lubricating the valves may in some instances obstruct the passageway through the valve due to the excessive lubricant interfering with other equipment that may be run into the well. Generally, each valve has to be lubricated hourly during operation. Typically, a high pressure stroking pump is used to force the lubricant into the desired areas of each valve. In the past the lubricant pump operator has been required to count the number of strokes the pump makes in order to determine the amount of lubricant pushed into each valve. Unfortunately, due to distractions at the wellsite is unusual for the lubricant pump operator to maintain a precise stroke count. Proper greasing decreases the cost of operating the well, improves reliability of the valves, and does not interfere with the proper functioning of other equipment within the wellbore.

Another problem is that many of the valves needing lubrication may have internal pressures of 15,000 psi. Therefore, in order to grease a valve under pressure (in order pump the grease in the first place) the pump must create sufficient pressure to overcome the pressure in the valve in order for the grease to flow into the valve. Currently utilized flow meters are paddle wheels or in line wetted meters. Unfortunately, even the lower pressure 10,000 psi units fail when operated in this grease environment. The sealing greases and additives destroy the flowmeters. The reliability, in particular of the frac valves is highly dependent upon the grease. The grease or lubricant protects the interior of the valve from the high amounts of proppant and other chemicals in the fluid which in turn moves through the valves.

In an embodiment of the current invention a lubrication flow meter has been designed primarily for use with frac valves on a wellhead. However, any device that needs lubrication under high pressure, including choke manifolds, blowout preventers, or any other production valves that are subject to high pressure may utilize such a flowmeter. In an embodiment the flow meter counts each half stroke of the pump until reset. Therefore, the meter is able to maintain a cumulative total of high-pressure grease that is pumped by the particular pump until it is reset. The pump may track the number of half strokes of the pump or it may track the number of full strokes of the pump. While a mechanical counter may be used it is envisioned that an electronic counter may be used. It is envisioned that non-volatile memory is used in the electronic counter to store the total amount of grease pumped prior to reset or other parameters concerning the amount of grease pumped such as how much grease is pumped per hour, per day, or per month. Other parameters that may be included in an electronic high-pressure flowmeter are the number of strokes made by the pump or the conversion of each stroke into a quantity of grease pumped for the quantity is rendered in whichever unit system as desired by the operator. For instance the volume of each stroke is determined and the parameter is input into the electronic flowmeter along with other information such as: each stroke pumping grease downstream or is grease merely pumped in one direction while the internal volume of the pump is refilled when the pump strokes in the opposite direction.

MOW nonvolatile memory will retain the information stored within it even when the memory loses power. By including an electronic counter the electronic counter may be remotely accessed by radio or via the Internet or the electronic counter may be directly accessed such as downloading the data into an external drive, removing the memory from the counter and accessing the data at a remote location, or even printing the stored parameters remotely or locally.

A lubrication flow meter system comprising a pump, a pressure sensor providing an electronic wellbore pressure indication, wherein the pump provides lubricant at greater than wellbore pressure, a frack valve having a through bore, a grease cavity, and a port between an exterior of the frack valve the grease cavity. A programmable logic controller switches on the pump at predetermined pressure or time intervals, wherein the programmable logic controller switches off the pump upon reaching predetermined pressure, time, or volume limits. An alarm is activated upon exceeding predetermined pressure, time, or volume limits

It is generally envisioned that the current embodiment of a high-pressure lubrication flow meter is a nonwetted system, i.e. none of the parts of the flowmeter contact the lubricant in the production string. The current embodiment uses a magnetic proximity sensor that senses a position indicator installed on the pump such that a magnet on the stroke arm of the pump will engage a magnet sensor at a location along the stroke of the pump. In some instances, the sensor may be on the stroke arm of the pump and the magnet is located along the stroke of the pump. In other instances, a light sensor may be utilized where the light sensor is located along the stroke of the pump and a stroke is sensed when the light source interrupted or in other cases when the light source is sensed.

When including a pressure sensor with lubrication flowmeter the lubrication flowmeter may be programmed to provide an alert when low pressure is sensed. Such low pressure could indicate a failure of a check valve, an air pocket, or the grease source being empty or low.

In an alternative to calculating the volume amount of greased pumped based on the displacement of each stroke of the pump is envisioned that the amount of grease pumped may be calculated based upon the size of an orifice where the pressure within the pump is monitored allowing the lubrication flow meter to determine the amount of grease passing through the orifice in a certain period of time. It is preferred that the pressure on both the upstream side of the orifice as well as the downstream side of the orifice are monitored.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a frack valve configured for greasing.

FIG. 2 is a top view of the frack valve of FIG. 1 configured for greasing.

FIG. 3 is a block diagram depicting the process for lubricating a frack valve.

DETAILED DESCRIPTION

FIG. 1 is a is a frack valve 10 configured for greasing. With an arrow 12 that indicates the flow of frack or other fluid into the valve 10. We have a gate 16, a first stem 18, and a second stem 20. The stems 18 and 20 move the gate 16 within the valve 10 to allow or restrict the flow of fracking fluid 12 through the valve 10.

FIG. 2 is a top view of the frack valve from FIG. 1. Port 30 is the through bore that passes through the body 11 of frack valve 10. The fracking fluid 12 passes into the frack valve 10 through port 30. In between the gate 16 and the body 11 is grease cavity 32 a first flow line 34 allows grease to flow into grease cavity 32 and eventually exiting grease cavity 32 into the interior through bore 40 as indicated by arrows 37. Grease also flows to exit the valve 10 through port 36 as the grease exits grease cavity 32 as indicated by arrow 39.

FIG. 3 is a block diagram depicting the process for lubricating a frack valve.

While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible.

Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter. 

1) A lubrication flow meter system comprising: a pump, a pressure sensor providing an electronic wellbore pressure indication, wherein the pump provides lubricant at greater than wellbore pressure, a frack valve having a through bore, a grease cavity, and a port between an exterior of the frack valve the grease cavity; a programmable logic controller that switches on the pump at predetermined pressure or time intervals, wherein the programmable logic controller switches off the pump upon reaching predetermined pressure, time, or volume limits. 2) The lubrication system of claim 1 wherein, an alarm is activated upon exceeding predetermined pressure, time, or volume limits. 